The Thunder have been rolling and tumbling ever since, right up through Friday’s Game 3 which it lost on its home floor to the Spurs, who took a 2-1 lead in their second-round series.

We’re no longer talking fathers and heirs apparent.

The Spurs look like they may never die, the Thunder like they could disappear in a poof.

The Spurs are now like America’s Team with everyone in the NBA rooting for them to knock off the Thunder — again — on the theory that Durant, a free agent on July 1, might be discouraged enough to leave.

With the salary cap jumping to $90 million, the two best teams, the Warriors and Spurs, will have a maximum slot they intend to offer KD.

Once the Thunder aspired to be the Spurs with owner Clay Bennett, a former minority owner in San Antonio, hiring GM Sam Presti out of their front office.

What happened?

First, Oklahoma City lost Games 2, 3, 4 and 5 to the Heat in the 2012 Finals.

Four months later, Presti traded James Harden to Houston for Kevin Martin, Jeremy Lamb and draft picks … because of $4.5 million difference on a four-year extension.

Oops.

Two years later the new TV deal took the Thunder from $31 million to $87 million annually, after the team had talked itself into thinking it was a poor tiny-market team that couldn’t afford Harden.

Then the young prodigies began getting older.

In 2013 Westbrook was lost with a knee injury in the first round.

The following season, he hurried back, went out following surgery to the same knee and wound up playing 46 games.

Last season Durant played 27 games after breaking a bone in his foot.

Nobody knows where Durant will go but here’s how it looks:

Thunder — We’ll say they’re even odds to keep him, the leader in the clubhouse.

If lots of players are goers, KD is a stayer. As a restricted free agent in 2010, he signed an extension before anyone in the press thought to ask about it.

His likeliest move now is sign a one-year deal to stay, or a two-year deal with an out next summer, enabling him to take as much as $40 million more as the cap mushrooms and make his decision at the same time as Westbrook in 2017.

“I think he’s going to test the water,” said UConn Coach Kevin Ollie, a former teammate of Durant, “but at the end of the day, Oklahoma City is something dear to his heart.”

Spurs — Come on in, the water’s fine.

Showing what a good team will do for you, this small market team in the sweltering humidity of South Texas has replaced the Lakers as the stars’ destination of choice.

Insiders say LaMarcus Aldridge actually wanted to sign with the Lakers but didn’t like their marketing-heavy presentation with Time Warner people at the meeting.

Instead, Aldridge came to San Antonio where it’s basketball first, last and always

KD could still be the No. 1 option there on a team with Aldridge at 30 and Kawhi Leonard at 24.

Let’s make them 5-1.

Warriors — Maybe KD likes the idea of being No. 2 to Steph Curry.

My guess is he’d prefer to have his own team.

Let’s make them 10-1.

Wizards — Durant is from the area. The Wizards, who have been getting ready to make this pitch for years, just hired KD’s old coach, Scott Brooks.

Insiders say it doesn’t matter. Let’s make them 50-1.

Clippers — NBA people thought they would try to sell KD on coming, then offer Blake Griffin to his native Oklahoma in a sign-and-trade.

As if to end that talk, Doc Rivers just said flatly they won’t trade Blake.

Let’s make it 25-1, on the assumption you can never say never.

Knicks — Everyone wants to play in New York, according to New Yorkers.

Of course, the Knicks are awful. They’re 1,000-1.

Lakers — I heard a team official talk about this day in 2011.

Unfortunately for them, it’s early in their rebuilding process, like day one.

They had better hope KD stays where he is for a year and gives them a chance to grow up.